The Food and Drug Administration on Monday approved two fixed-dose combination anti-HIV pills by Gilead Sciences and GlaxoSmithKline that combine previously approved antiretroviral medications into a single pill to simplify dosing regimens.

The FDA approved Gilead Sciences' Truvada, which combines the company's nucleotide reverse transcriptase inhibitor Viread and its nucleoside drug Emtriva. Truvada received accelerated marketing approval just four months after being filed with the FDA. Truvada combines 200 milligrams of Emtriva with 300 milligrams of Viread in a single tablet taken once a day with other anti-HIV medications. Gilead will sell Truvada for $650.83 for a 30-day supply. Truvada will be shipped to wholesalers by the end of the week.

The FDA on Monday also approved Glaxo's Epzicom, which combines the company's previously approved nucleoside reverse transcriptase inhibitors Ziagen and Epivir into a single, once-daily pill. Epzicom was approved 10 months after its marketing application was filed with the FDA. Glaxo will sell Epzicom for $621.60 for a 30-day supply. The company also will issue vouchers for a free 60-day supply of the drug for all HIV-positive patients just beginning antiretroviral therapy and for those who need to switch their drug regimens. The vouchers will be provided through health care providers.

Gilead officials said that the company will include Truvada in its Gilead Access Program, which provides access to anti-HIV medications on the developing work at no-profit pricing. Glaxo also said Epzicom will be sold in poor nations at a no-profit price. The FDA approval also makes both drugs available for purchase through the President's Emergency Plan for AIDS Relief, which aims to provide antiretroviral therapy in 15 poor nations in Africa, the Caribbean, and Asia.

FDA officials say the fixed-dose combination pills will help HIV-positive people better stick to their antiretroviral drug regimens. "Simplifying treatment regimens by reducing the number of pills and times per day patients need to take them provides significant public health benefits," said acting FDA commissioner Lester Crawford in a press release.